The No Rudder Spin

whifferdill

whifferdill

Line Up and Wait
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whifferdill
Learned something new about my airplane last night. I've heard others say it's easy to get into a spin without rudder in various airplanes. I had not experienced this, but also never had a reason to try very hard. So out of curiosity, I took the Pitts up yesterday evening and tried. I kept my feet off the rudder and first tried various straight and accelerated power-off stalls done with full aileron in both directions. These would turn into a "spiraling stall", but none turned into true spins after quite a bit of time waiting to see if anything developed. Each time, simply unloading the stick immediately broke the stall and returned the plane to normal flight. Do this with a spin and not only will it not recover, but it will accelerate.

Next I tried the same thing, only with power. Power-on stall, full left aileron, and the plane rolled over, but only did a slightly spiraling flat mush. Again waited to see if a spin developed. None did, and unloading the stick immediately broke the stall.

But I actually got a spin going with a power-on stall and full right aileron. It wallowed around for several seconds and then slowly stabilized into a flattish spin to the left. Pushing the stick forward and waiting did not slow down the rotation. This one actually took opposite rudder, and actually was a spin. Stopped immediately with right rudder, much quicker than a normal spin with rudder.

Obviously the propellor slipstream yaws the plane to the left anyway, but it took right aileron to further stall the left wing enough to actually produce enough lift differential to produce autorotation.

Anyway, I just found this very interesting and thought I'd share. I think you'd really have to work to get a no-rudder spin in most airplanes. The Pitts has very neutral characteristics and is happy to do almost anything you ask. But it did take some effort to get a no-rudder spin.
 
what airport do you fly out of in NC?

the slipstream is kinda like feeding in left rudder. ever try giving it full power just as you are going into a power off stall? (I have not) maybe the torque from the acceleration of the propeller blade will give you some extra kick needed to get into a spin
 
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Hey, same as you! Stop by A14 sometime if you're out on a weekend. I'm usually out at some point on any weekend with decent Wx. I'm the only one there with one of these little biplane "bugs" as some might say. I assume you fly with WOC?

Adding power right after a power-off stall should have the same eventual effect as a power-on stall.

Eric
 
whifferdill said:
Learned something new about my airplane last night. I've heard others say it's easy to get into a spin without rudder in various airplanes. I had not experienced this, but also never had a reason to try very hard. So out of curiosity, I took the Pitts up yesterday evening and tried. I kept my feet off the rudder and first tried various straight and accelerated power-off stalls done with full aileron in both directions. These would turn into a "spiraling stall", but none turned into true spins after quite a bit of time waiting to see if anything developed. Each time, simply unloading the stick immediately broke the stall and returned the plane to normal flight. Do this with a spin and not only will it not recover, but it will accelerate.

Next I tried the same thing, only with power. Power-on stall, full left aileron, and the plane rolled over, but only did a slightly spiraling flat mush. Again waited to see if a spin developed. None did, and unloading the stick immediately broke the stall.

But I actually got a spin going with a power-on stall and full right aileron. It wallowed around for several seconds and then slowly stabilized into a flattish spin to the left. Pushing the stick forward and waiting did not slow down the rotation. This one actually took opposite rudder, and actually was a spin. Stopped immediately with right rudder, much quicker than a normal spin with rudder.

Obviously the propellor slipstream yaws the plane to the left anyway, but it took right aileron to further stall the left wing enough to actually produce enough lift differential to produce autorotation.

Anyway, I just found this very interesting and thought I'd share. I think you'd really have to work to get a no-rudder spin in most airplanes. The Pitts has very neutral characteristics and is happy to do almost anything you ask. But it did take some effort to get a no-rudder spin.
Click to expand...

I have some interest in aerobatics and emergency recovery so please take my question as neophyte curiosity.

How did you discover a maneuver that will make recovery not possible, yet you obviously did? What did you do to recover?
 
whifferdill said:
Hey, same as you! Stop by A14 sometime if you're out on a weekend. I'm usually out at some point on any weekend with decent Wx. I'm the only one there with one of these little biplane "bugs" as some might say. I assume you fly with WOC?

Adding power right after a power-off stall should have the same eventual effect as a power-on stall.

Eric
Click to expand...

I've seen you out there on more than one occasion! That biplane looks like way too much fun. One of these days I'm going to take a lesson in that red Citabria. I am with WOC, weaver is my instructor. i'll drop by sometime!

Ren
 
Jaybird180 said:
I have some interest in aerobatics and emergency recovery so please take my question as neophyte curiosity.

How did you discover a maneuver that will make recovery not possible, yet you obviously did? What did you do to recover?
Click to expand...

I think he meant that letting go of the stick (i'm guessing he had up elevator in) was not enough to recover. He probably had to do the down elevator and opposite rudder :)
 
1. It takes yaw to cause a spin. The yaw in this case is caused by both P-factor (downgoing prop blade at higher AoA on RH side and pulling nose left), and spiralling prop slipstream striking left side of fin and pushing nose left.

2. Once in a spin, relaxing elevator will not normally stop the spin quickly, if at all. Opposite rudder is required to stop the rotation. If the airplane is rotating, the masses of the nose and tail try to come into the same plane of rotation, which tends to raise the nose and keep the thing stalled and therefore spinning. Stopping the rotation allows the nose to fall (if elevator is relaxed) and break the stall.

Dan
 
Jaybird180 said:
I have some interest in aerobatics and emergency recovery so please take my question as neophyte curiosity.

How did you discover a maneuver that will make recovery not possible, yet you obviously did? What did you do to recover?
Click to expand...

Pushing the stick forward will recover from a stall when not in a developed spin.

Pushng the stick forward will accelerate a developed spin (whee!) - to recover you have to pull the stick back (or, in some aircraft, let go) and convert back to a normal spin then do the normal spin recovery (Rudder FIRST to stop rotation, then stick forward)

More than a few people have spun all the way into the ground. I assume at least some had thought they had done the proper recovery but in reality sat there with the stick forward in an accelerated spin.
 
Capt. Geoffrey Thorpe said:
More than a few people have spun all the way into the ground. I assume at least some had thought they had done the proper recovery but in reality sat there with the stick forward in an accelerated spin.
Click to expand...

Or even crossed over into an inverted spin without realizing it.

In my S-1S, I thought it was interesting that if I pull the stick fully back to accelerate an inverted spin (or push forward for an upright spin) that it will eventually recover by applying opposite rudder while leaving the stick in the fully accelerated position. Of course, in the same situation, it recovers much more quickly if I return the stick to the position the spin first started with before applying opposite rudder, then neutralizing the stick.

I found this interesting because of I've heard pilots of other Pitts models mention that fully reversing the elevator during a spin (before applying opposite rudder) will blank the rudder enough to prevent recovery unless the stick is returned to the original spin position (aft if upright, forward if inverted). I never specifically tried this in anything but my S-1S.

The Bryan Jensen crash has gotten me to thinking about all this stuff again.
 
whifferdill said:
Learned something new about my airplane last night. I've heard others say it's easy to get into a spin without rudder in various airplanes. I had not experienced this, but also never had a reason to try very hard. So out of curiosity, I took the Pitts up yesterday evening and tried. I kept my feet off the rudder and first tried various straight and accelerated power-off stalls done with full aileron in both directions. These would turn into a "spiraling stall", but none turned into true spins after quite a bit of time waiting to see if anything developed. Each time, simply unloading the stick immediately broke the stall and returned the plane to normal flight. Do this with a spin and not only will it not recover, but it will accelerate.

Next I tried the same thing, only with power. Power-on stall, full left aileron, and the plane rolled over, but only did a slightly spiraling flat mush. Again waited to see if a spin developed. None did, and unloading the stick immediately broke the stall.

But I actually got a spin going with a power-on stall and full right aileron. It wallowed around for several seconds and then slowly stabilized into a flattish spin to the left. Pushing the stick forward and waiting did not slow down the rotation. This one actually took opposite rudder, and actually was a spin. Stopped immediately with right rudder, much quicker than a normal spin with rudder.

Obviously the propellor slipstream yaws the plane to the left anyway, but it took right aileron to further stall the left wing enough to actually produce enough lift differential to produce autorotation.

Anyway, I just found this very interesting and thought I'd share. I think you'd really have to work to get a no-rudder spin in most airplanes. The Pitts has very neutral characteristics and is happy to do almost anything you ask. But it did take some effort to get a no-rudder spin.
Click to expand...

That is a very interesting post. Pro spin aileron was enough to cause a spin, in combination with the prop slip stream. Makes sense.

I tried different combinations spining my Mustang. If I yawed first then loaded the wing and stalled it took a bit longer to lock into a spin.

If I stalled first and put in full left rudder it would always do a proper spin. Spins to the left required a bit more deliberation before it would lock in.
 
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